Electropneumatic-brake device



Dec. 19, 1922. 1,439,039. T. H. THOMAS.

, ELgcmoPNEuM/UCBBAKEnsvacE.

msn 11.111.11.1921.

24 22 BY`% gt UNITED STATES PATENT OFFICE.

THOMAS H. THOMAS, OF EDG-EWOOD, PENNSYLVANIA, ASSIGNOR TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF VILMERDING, PENNSYLVANIA, A CORPORATION or PENNSYLVANIA.

ELECTROPNEUMATIC-BRAKE DEVICE.

Application filed March 17, 1921.

[o ZZ ifi/mm t may con/cera.'

Be .it known that I. THOMAS H. THOMAS, a citizen of the United States, residing at Edgewood. in the county of Allegheny and State oit Pennsylvania, have invented new and useful` Improvements in Electropneumatic-Brake Devices, of which the follow ing is a specification.

This invention relates to electro-pneumatic brakes, and more p particularly to means Ator controlling the energization and decncrgization ot the brake magnets.

It has been found that the deenergization olf' a brake magnet occurs much more rapidly than the energization ot the same magnet and thereby undesired operating results are sometimes obtained. For example; assume that two magnets A and B are employed tor controlling the brakes. The magnet A may be energized and the magnet B deenergized in one position ot the controlling brake switch such as running position, while the magnet A may be deenergized and the magnetiB energized in another position, such as service application position. And further, the equipment may be so designed that the dcenergization ot' both magnets A and B will canse an emergency application of the brakes.

Tg5. under the above conditions, the brake switch is turned from running position to sei-ivre application position, the magnet A will be quickly deenergized, but the mag energines slowly, with the result that both magnets may be practically deenergizcd upon movement ot the brake switch to service pos' ion. so that an emergency application. ci Lhe brakes is produced when not intended.

The principalv object o1 my invention is to provide n .ns for overcoming the above di'tiiculty.

ln the accompanying drawing; Fig. 1 'is a vertical sectional view ot an apparatus e1n bodying my iiivention; Fig'. 2 a diagram showing the positions ot the brake switch and the circuit connections to the brake magnets, and Fig. 3 a sectional view of the brake valve device in service application position.

In Fig. 1 or the drawing is shown a brake valve device comprising a casing 1 having a valve chamber 2, containing a rotary valve 3 adapted to be operated by a handle 4.

Serial No. 453,009.

According to my invention, a switch device is provided, comprising a casing 5 having a piston chamber G, containing a piston 'i'. The stem 8 of the piston 7 is pivotally connected to a switch arm 9, fulcrumed on the pivot pin 10 and said switch arm carries at its movable end a contact bar 11 so shaped that in one position ot the switch arm 9, contact lingers 12 and 13 are connected through the contact bar 11, while in another posi tion, fingers 12 and 14: are connected together.

lVliile not shown in the drawing, it will be understood that the brake switch is operated by the movement ot the brake valve handle 41;, and as shown in Fig. 2, the brake switch may be provided with stationary contacts 15, 16. 1T, and 1S, adapted to engage the movable drum contact 25.

The contact 15 is connected to the B wire which connects the brake magnets B throughout the train, the Contact 16 to the A wire, leading to the brake magnet A, the contact 17 to a source ot current 19, and Contact 1S to a supply wire 20, which is connected to the finger 12 of the switch device 5.

The contact finger 14 ot the switch device 5 is connected to the B wire, while contact finger 13 is connected to the A wire.

In release, running, and holding positions ot the brake valve device 1, a port 21 supplies tiuid under pressure from the rotary valve chamber 2, through pipe Q2 to the piston chamber G, while in service position, as shown in Fig. 3, the pipe 22 is connected, through a cavity 23 in the rotary valve 3 with an exhaust port 24.

When the brake valve and brake switch are in running position, the B wire is deenergized, while the A wire is energized, so that the brake magnet l?) is decnergizcd and the brake n'lagent A is energized.

ln this position of the brake valve device 1, fluid under pressure is supplied to the piston cylinders 6, so that piston 7 holds the switch arm 9 in the position shown in Fig. 1, in which the contact fingers 12 and 13 are connected.

It the brake valve and brake switch are turned to service application position, connection is made through the brake switch drum for energizing the B wire and for deenergizing the A Wire, but it will now be noted that the ,fr wire will still be energized `iii-om the source oiE current i9, through the wire 20 and the contact lingers l2 and i3 ot the switch device 5, so long as the switch arm 9 holds the contact bar ll in its upper pdsition.

ln the service application position oli the brake valve device, as shown in Fig. 3, the pipe 22 is vented to the. exhaust port 24, but it requires a predetermined time interval to reduce the pressure in piston chamber 6, so as to permit the piston 7 to move down and this interval is made such that the magnet B will be fully energized before the switch arm 9 will be moved to open the supply circuit connection through the contact bar l1 to the A wire.

'llhe volume ot' the pipe 22 and piston. chamber 6 may be sufficient Yfor this purpose, but iii necessary a small volume res-h ervoir may be connected to the pipe 22 or the vent port area in the service position may be restricted to delay the release ot fluid from the piston cylinder (l.

By the above means, the deenergization of one brake magnet by the movement ot the brake switch is delayed to permit the full energization of another brake magnet, and thus the possibility of both magnets being deenergized at the same time is prevented, when not intended.

In a similar manner, if the brake valve and brake switch are turned from service position to running position, the B wire will be held energized through the contact bar ll, although the circuit is opened at the brake switch, until the iuid pressure supplied through the brake valve device to the piston chamber 6 is sutlicient to raise the piston 7. i

Having now described my invention, what I claim as new and desire to secure by Letters Patent, iszl. In an electro-pneumatic brake, the comf bination with a bralre magnet for controlling the brakes, oli a brake switch having positions itor opening and closing the circuit of said magnet and an auxiliary switch device tor also controlling the opening and closing of the magnet circuit.

" 2. In an electro-pneumatic brake, the combination with brake magnets for controlling the brakes, ol a brake switch having positions 'for energizing and decnergizing said magnets and an auxiliary switch device ttor maintaining a brake magnet energized upon movement of the brake switch to a position for deenergizing said magnet.

3. ln an electro-pneumatic brake, the combination with brake magnets for controlling the brakes, of a brake switch having positions or energizing and deenergizing said magnets and an auxiliary switch device for holding a brake magnet energized upon movement ot the brake switch to a position for deenergizing said magnet, the auxiliary switch device operating to deenergize said magnet after a predetermined time interval.

4t. In an electro-pneumatic brake, the combination with brake magnets tor controlling the brakes, olf a brale switch having positions for energizing and deenergizing said magnets, a fluid pressure operated switch device `for holding a brake magnet energized in a position ot the brake switch for deenergizing said magnet, and means operated upon movement of' the brake switch to said position for venting fluid under pressure from said switch device.

5. ln an electro-pneumatic brake, the combination with a pair of brake magnets, of a brake switch having a position for opening the circuit of one magnet and closing 'the circuit of the other magnet and a switch device for closing an auxiliary circuit through the first magnet and operating to open said circuit aiter a time interval.

6. ln an electro-pneumatic brake, the combination with a pair of brake magnets A and B, oi a brake switch having one position for energizing the A magnet and deenergizing the B magnet and another position t'or deenergizing the A magnet and energizing the B magnet, an auxiliary fluid pressure operative Iwitch device having one position for energizing the A magnet and deenergizing the B magnet and another position for deenergizing the A magnet and energizing the l5 magnet, and a brake valve device having one position for supplying iuid under pressureto said auxiliary switchI device and another position for venting fluid from said switch device.

ln testimony whereof l have hereunto set 

